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Poster: William Tell Date: Jul 26, 2008 4:30pm
Forum: GratefulDead Subject: Not a poll, nor a searchable ?, nor music, nor Rob's undies...MP4?

Sorry, it may have been asked before, but my search came up empty: are MP4 roughly equivalent to MP3 in terms of sonic quality (ie, degree of compression)? Have performed a few experiments via Nero and it seems that MP4 is BETTER than MP3, but tough call...

Anyone happen to know?

Thanks.

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Poster: spacedface Date: Jul 27, 2008 3:00am
Forum: GratefulDead Subject: Re: Not a poll, nor a searchable ?, nor music, nor Rob's undies...MP4?

Tricky because MP4 can contain MP3 or the more efficient at the same bitrate "AAC" (Apple uses it unless you specify mp3 in iTunes).

More on AAC:
http://en.wikipedia.org/wiki/Advanced_Audio_Coding

The following kinds of data are recommended (for compatibility reasons) to be embedded in MPEG-4:

* Video: MPEG-4, MPEG-2 and MPEG-1
* Audio: MPEG-4 AAC, MP3, MP2, MPEG-1 Part 3, MPEG-2 Part 3, CELP (speech),TwinVQ (very low bitrates), SAOL (midi)
* Pictures: JPEG, PNG
* Subtitles: MPEG-4 Timed Text, and/or xmt/bt text format (means that subtitles have to be translated into xmt/bt)
* Systems: Allows animation, interactivity and DVD-like menus

Here are some file extensions used on files that contain data in the *.mp4 format:

* .mp4: official extension, for audio, video and advanced content (see above) files
* .m4a: for audio-only files; can safely be renamed to *.mp4, though opinions differ on the wisdom of this.
* .m4p: FairPlay protected files
* .mp4v, .m4v: video-only (sometimes also used for raw mpeg-4 video streams not in the *.mp4 container format)
* .3gp, .3g2: used by 3G mobile phones, may also store content not specified directly in the *.mp4 specification (H.263, AMR, TX3G)

And Flash versions are called .f4v

This post was modified by spacedface on 2008-07-27 10:00:48

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Poster: William Tell Date: Jul 27, 2008 6:52am
Forum: GratefulDead Subject: Re: Not a poll, nor a searchable ?, nor music, nor Rob's undies...MP4?

Thanks SF! Searched a bit on it, and was more out of curiosity than real interest in it...noticed that Nero would allow either MP3 "pro" or MP4, in addition to WAV, for ripping of CD files, and it got me thinking...